Of course, Trump doesn't actually need a majority of votes to
win. As Business Insider has noted before,
Trump only needs 49.4% of the vote in order to engineer a 294
electoral college vote victory (candidates need 270 of 538 votes
to win).

And he can get that 49.4% as long as white voters turn out for
him in greater numbers than they did for Mitt Romney in 2012.

Back in April 2016, when Trump was 12 points behind Clinton in
the polls,
I advanced the theory that Trump could unexpectedly become
president if there was one key demographic shift among
American voters*: If Trump received 66% of the votes of
"non-college educated white people," rather than the 60% that the
Republicans received in 2012, he would win a majority in the
electoral college, giving him the presidency with
just 49.4% of the total vote.

Since then, Trump has pursued a racially charged campaign and won
the support of "alt-right" white nationalists, who are suddenly
popular in social and online media. Trump has tapped into a pool
of white resentment at the way caucasian voters have seen their
wealth, power, and privilege slip as America becomes an
increasingly diverse nation, and whites become merely one racial
minority within it.

You can adjust the demographic vote shares on the
FiveThirtyEight interactive map to see various speculative
scenarios. In order to create a Trump victory, the
smallest voter shift required is moving Republican
support among "non-college educated white people" from 60% to
66%.

When you do that, here is how it plays out in
2016:

Trump wins Ohio and
Florida.

Republicans win 66% of
"non-college educated white
people."

Trump wins a majority in the
electoral college with just 49.4% of the national vote.

The first is that even in my Ohio/Florida/whites scenario,
Clinton still gets a majority of the national vote, and usually
that will create a majority in the electoral college too. This
theory is highly dependent on Trump winning key states. The
marginal states of New Mexico, Wisconsin, Colorado, and New
Hampshire all have to flip from Democrat to Republican in this
cycle along with Ohio and Florida.

It also ignores the expectation that the population of
"non-college educated white people" is in decline.

"Non-college-educated
whites skew older and rural and will be 46 percent of
eligible voters in 2016, down from 49 percent in 2012," according
to FiveThirtyEight. That suggests the odds are stacked against
Trump.

The only way Trump overcomes this is if he can motivate a ton of
new white people who didn't previously vote, and get them to the
polls. Whites
make up 72% of the electorate, as my colleague Josh Barro
points out.

So it's do-able.

It is probably Trump's most likely route the White House right
now.

*I updated my theory
in May and
July and
September. Silver also updated his stats regarding the
percentage of voters who are non-college educated whites.
Previously, his site said their portion would decline from 39% to
33% of the vote between 2012 and 2016.